Once I passed the tests, my training began. I was told to present myself with personal effects suitable for a two-night stay in Tel Aviv. The address turned out to be a well-appointed apartment, where I was met by a half-dozen men and women who looked me over with bemused detachment. After some basic introductions, their apparent leader, a tall, dark-haired man with piercing blue eyes named Halleck, told me to go into the next room and devise a cover story for both my identity and my reason for being in Israel. “Let your imagination go wild,” he told me. “The only rule is you can’t be Canadian. We want to make this challenging.”

After fifteen minutes or so, I came up with what I thought was a winner: I was a U.S.-based journalist doing a background story on Tel Aviv for the Los Angeles Times. Once I worked out the biographical details, I came out of the room quite pleased with myself, and presented my invented identity to Halleck and his colleagues.

Unbeknownst to me, this was a stock exercise in the intelligence business. I was being asked to create something that every covert intelligence operative must have: a bogus but believable cover story about who you are, where you come from, and what you’re doing. In intelligence parlance, this assumed identity is known as a legend. It sounds easy, but it’s not, as Halleck demonstrated to me in about thirty seconds.

“Nice to meet you, Fred Porter,” he said in a casual tone after I’d introduced myself. “Welcome to Israel. May I ask where you’re staying? The Hilton you say? Nice place. What’s your room number? I’d like to call you later in the day.”

After I stammered who knows what unconvincing nonsense, he went to work on the rest of my cover story. “You sound disoriented,” he said. “Why don’t we call up your editor in L.A. I bet he’s worried. You must know the number off the top of your head, right? What’s that? You don’t know your own area code?”

I felt the eyes of Halleck’s entourage on me, but they didn’t interrupt the conversation. I was unnerved, and I couldn’t help but feel that I was failing an audition of sorts — a kind of American Idol for spies, if you will — and at that particular moment, I was warbling hideously. After enduring some constructive criticism, I was sent back into the next room with my tail between my legs. Creating a convincing story is not the hard part, I realized. The challenge was in concocting a convincing story that is also virtually impossible to check out.

It took me several tries, but I eventually hit on something that held up under Halleck’s preliminary probing. I was still a journalist, but for a small Christian community college with a generic-sounding name (this was the era before Google, remember). I was staying at a youth hostel. No, I couldn’t remember its name and there are hundreds in Israel. And I’d checked out that morning anyway. Once my identity and raison d’être had been established, I was bundled into a van with Halleck and some of his retinue, and we drove into the epicentre of a bustling Tel Aviv afternoon.

There is a scene in the film Spy Game in which Robert Redford, the old CIA hand, takes his protégé, Brad Pitt, onto the streets of Berlin and runs him around to test his smarts. This was more or less what I was doing. I had to appear on a randomly chosen apartment balcony after convincing the tenant to allow me access; get the first three names from a hotel register; start a conversation with a complete stranger and hold his attention for twenty minutes; put a device in a public phone mouthpiece in the heart of the Hilton Hotel lobby without being noticed; and a whole host of other odd but challenging tasks.

In each case, I had to rely not only on an invented identity — my legend, or “status cover” — but also on what I later learned to refer to as my operational cover, that is, my fictional motive for being in a particular place and doing a particular thing at a particular time. A legend stays with you for years, but an operational cover is often invented on the spot.

One thing they don’t show you in the spy movies: what the agents do at night. No, I’m not referring to bedding beautiful women with names like Plenty O’Toole and Pussy Galore. When the sun goes down, spies morph into paper-pushing bureaucrats. (I suppose that Canadian government job was good for something.) There is a saying in the Mossad: “If you complete a mission and don’t report it, the mission never happened.” I was instructed to write reports about all of my activities during the day in any format I saw fit (this being 1988, I recorded everything in longhand). By the time my head hit the pillow, I was exhausted.

As I performed my various tasks over the next couple of days, Halleck and his colleagues sat in cafés and watched me. On the odd occasion, one of them would ask me why I did what I did, and I’d try to explain my thought process. These were not puzzles that had any correct answer. Rather, the idea was to test my judgment and ability to improvise. There was no going back to the office and thinking about it. I had to solve problems then and there.

In some cases, the tasks seemed plain impossible. But more often than not, I surprised myself. Hotel staff, I knew, would not make a guest registry available to anyone who asked. So I simply told the desk clerk that I had the camera of one of their guests, and that the young lady had given me her last name but I had forgotten it. “Look,” I said in a pleading tone, “it’s a very expensive camera and I’d like to return it to her . . . and truth be told, I really like her and would like to see her again . . . .”

I found that, with a good story and a hint of personal disclosure, most people will try to meet you halfway — say, turning the registry in your direction so you can scan it, without actually handing it to you. In other cases, where accomplishing the task just wasn’t in the cards, I had to realize as much and back off rather than force matters and cause a security problem. The adage that smart agents live to fight another day is an important principle in intelligence work.

The tests varied, but they all had the same goal: to see how far I could be pushed before I broke cover. In the spy business, I was gradually learning, you simply never break cover. A spy’s cover is the most important weapon in his or her professional arsenal. These tests don’t have a high pass rate because many promising candidates break cover at the first hint of a threat. It’s a natural response: reverting to your true self feels like a safe move. It’s an instinctive way of saying “I’m not playing anymore.” Those who can resist are highly valued by intelligence services.

I don’t know what it says about me — that I’m a good liar or a decent actor, or that I just don’t like to fail a test — but I never broke cover, not once. After two days, Halleck and the anonymous ringleaders who’d been putting me through my paces told me I’d passed. No, I was not a Mossad officer yet — nowhere near, in fact. But I’d made it past the first big hurdle. They told me to go home. They’d call me when the next stage was set to begin.